1389
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1856
- Proper Divisor Sum (Aliquot Sum)
- 467
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 924
- Möbius Function
- 1
- Radical
- 1389
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 127
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of partitions of floor(5n/2)-1 into n nonnegative integers each no more than 5.at n=20A001976
- Number of unlabeled unit interval graphs with n nodes.at n=8A005217
- Numbers k such that 10*3^k + 1 is prime.at n=16A005539
- Coordination sequence T2 for Zeolite Code LTN.at n=26A008141
- Coordination sequence T1 for Zeolite Code PHI.at n=27A008227
- Composite numbers that are equal to the sum of the first k composites for some k.at n=34A013921
- Numbers k that divide s(k), where s(1)=1, s(j)=21*s(j-1)+j.at n=18A014872
- [ Sum{(log(j)-log(i))^2} ], 2 <= i < j <= n.at n=46A025206
- High temperature series in v^2 = tanh(J/kT)^2 for spin-1/2 Ising partition function on 4D simple cubic lattice, divided by 2/(1+v)^4.at n=4A030044
- Numbers k such that A030787(k)=4.at n=48A030796
- Twin lucky numbers (upper terms).at n=42A031159
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 24.at n=11A031522
- Lucky numbers with size of gaps equal to 6 (lower terms).at n=46A031888
- Lucky numbers (A000959) ending with digit 9.at n=44A032589
- a(n) = floor( (Pi/e)^n ).at n=50A032739
- Coordination sequence T3 for Zeolite Code SBE.at n=30A033606
- Decimal part of a(n)^(1/6) starts with n so that a(n)<a(n+1).at n=34A034071
- Concatenation of 'nextprime(a(n)) and a(n)' and 'a(n) and nextprime(a(n))' are both prime.at n=45A034595
- StirlingS2[ n,m ] triangle summed down the columns.at n=30A036560
- Numbers whose maximal base 8 run length is 3.at n=32A037994